Rotary engine.



PATENTED AUG. 2, 1904.

W. M. HOFFMAN.

ROTARY ENGINE.

APPLIOATIOH FILED 061224, 1902. nnnnwnn us. a, 1904.

2 SHEETS-SHEET 1.

K0 MODEL.

Te I 7 y A 1 ///%//a PATENTED AUG. 2, 1904.

W. M. HOFFMAN.

ROTARY ENGINE.

APPLICATION FILED OUT. 24, 1902. Rnnnwnn JAN. 5, 1904.

2 SHEETS-SHEET 2.

H0 MODEL.

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W z'fnesses Patented August 2, I904.

UNITED STATES PATENT OFFICE.

IVILLIAM M. HOFFMAN, OF BUFFALO, NEIV YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO GLOBE POIVER COMPANY INC.

NEIV YORK.

, A CORPORATION OF ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 766,696, dated August 2, 1904.

Application filed October 24,1902. Renewed January 6, 1904. Serial No. 187,982. (No model.)

To all whom it may concern.-

Be it known that I, IVILLIAM M. HOFFMAN, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Rotary Engines, of which the following is a specification.

This invention relates to a rotary engine in which the casing or cylinder and the pistonhub are rotatably mounted eccentrically relative to each other and are both rotated by the action of steam or other suitable motive fluid against pistons connecting the casing and piston-hub.

The object of the invention is to provide a rotary engine of simple, durable, and inexpensive construction which can be operated economically and in which the maximum efficiency is obtained and the wear is reduced to the minimum.

In the accompanying drawings, consisting of two sheets, Figure l is a longitudinal central section of a rotary engine embodying the invention. Fig. 2 is a section in line 2 2, Fig. 3, through the eccentric journal for the pistonhub. Fig. 3 is a transverse section through the engine in line 8 3, Fig. 1. Fig. 4 is a perspective view of the eccentric journal for the piston-hub.

Like letters of reference refer to like parts in the several figures.

A represents the casing or cylinder, in which the pistons and hub carrying the same are inclosed and operate. The casing may be of any suitable form and constructed in any convenient manner. In the construction shown in the drawings it consists of two heads or disks B, which are connected by an annular body or ring O, to which the heads are secured by bolts or otherwise and which is preferably made hollow for the sake of lightness. The casing is rotatably mounted, for instance, on a stationary hollow shaft or axle D, which passes through central bearing-hubs (Z on the opposite heads of the casing. The shaft is stationarily supported in any suitable manner in standards (Z.

The stationary shaft D is provided inside of the casing with a hollow eccentric enlarge ment E, which constitutes a journal for the rotary hub carrying the piston blades or plates. The bore of the hollow shaft is divided by a central partition 1; into inlet and exhaust passages c (1* for the steam or other motive fluid, and the opposite ends of the shaft may be suitably fashioned for coupling thereto supply and exhaust pipes (not shown) for the motive fluid. The hollow eccentric journal E is divided by a longitudinal partition f into chambers f" f which respectively communicate with the inlet and exhaust passages of the stationary shaft, and the circular wall of the eccentric journal is provided with inlet and exhaust ports communicating, respectively, with the chambers f" f of the journal.

H represents a piston hub or ring which is journaled to rotate freely on the eccentric journal E. The hub shown in the drawings consists of a hollow body formed by parallel annular side walls connected by longitudinal partitions or ribs h, which divide the hub into a plurality of steam-spaces open at the inner and outer circumferences of the hub and adapted in the rotation of the hub on the jouring and the piston-hub, being disposed equidistant around the periphery of the pistonhub. In the construction shown the inner ends of the pistons are provided with hingelugs 27, which are seated in sockets formed in the hub between the steam-passages thereof and hinged or pivoted to side lugs 2 on the piston-hub by pivot-pins 11 The outer ends of the pistons slidably engage in slots j,

Instead of thus forming the hub it can 7 formed in cylindrical blocks J, which are journaled to oscillate in bearing-sockets and 1' provided therefor in the body and opposite heads of the casing or cylinder. Any other suitable pivotal connection between the pistons and piston-hub and sliding and oscillating connection between the pistons and the casing may be employed, and the pistons could be hinged to the casing and have a sliding oscillating connection with the piston-hub without departing from the scope of this invention.

The piston-hub and easing or cylinder are caused to rotate together by suitable means, such as studs K, which project from the piston-hub and slidingly engage in slots in the inner faces of the heads of the casing. This connection between the piston-hub and casing adds greatly to the smooth easy operation of the engine and greatly reduces the wear on the pistons and connections between the latter and the casing and piston-hub. Without this connection, the pistons being pivoted to both the casing and piston-hub, some independent relative movement of the casing and pistonhub would be permitted, which would result in a jerky movement of the parts accompanied by noise. If the pistons were rigid with the hub or casing or had a simple sliding connection therewith and were relied upon to carry the hub and easing together, a very considerable leverage would be exerted by the pistons on their connections or packings and the latter would be soon worn away, rendering the engine useless. In the construction described the pistons have a very easy sliding movement in the oscillating blocks and cannot bind or clamp therein and wear the blocks or any packings for the pistons.

The rotary motion of the engine is transmitted in any desired manner. For instance, the casing A can be shaped to constitute a belt-pulley and operate a drive-belt running thereon, or a drive pulley or wheel (not shown) can be secured to one-of the hubs cZ projecting from the heads of the casing. Packings are provided at the points where it is necessary to make fluid-tight joints; but such packings have been omitted from the drawings, as they are no wise necessary to a complete understanding of the invention.

The operation of the engine is as follows: Assuming the parts to be in the position indicated by full lines in Fig. 3, steam or other motive fluid from any suitable source of supply is admitted to the inlet-passage e of the stationary shaft and passes thence through the chamber f and inlet-port g of the eccentric journal and the steam-space in the piston-hub into the piston-chamber behind the piston I, which is at the right in Fig. 3. As the exposed area of the said piston is greater than the exposed area of the next succeeding piston I, which is at the bottom in Fig. 3 and which acts as an abutment, the preponderance of ters with and uncovers the exhaust-port g to permit the fluid behind the piston to exhaust. The exhaust-port is uncovered at that point in the rotation of the parts when by reason of the eccentricity of the piston-hub and easing the exposed areas of the piston I and next succeeding piston I are equal. The motive fluid acts in this manner successively on the several pistons. By proportioning the parts properly the motive fluid can be cutoff before the opening of the exhaust-port and the fluid caused to act expansively between the times of cut-off and the opening of the exhaust-port in a wellknown manner.

In an engine constructed as described the wear due to friction is very small,for the reason that the principal friction is on the stationary shaft and eccentric journal and the surfaces of the piston-hub and easing bearing thereon, and these surfaces being near the axes of rotation of the casing and'piston-hubthe leverage of the friction isslight. Owing to the arrangement of the pistons and the oscillating bearing-blocks J therefor there is little wear between these parts. The fluid-pressure on the pistons and oscillating blocks presses the pistons against the walls of the slots in the blocks and the latter against their bearingsockets in the casing, thus effecting fluid-tight joints between these parts and preventing the leakage of fluid past the outer ends of the pistons. pistons also prevents any hammering or clicking thereof and renders the operation of the engine practically noiseless.

I claim as my invention 1. The combination of a casing and pistonhub which are rotatably mounted eccentrically relativeto each other and separated bya piston-space, a plurality of pistons connecting said casing and piston-hub and bridging said piston-space, and means for admitting and exhausting motive fluid to and from said pistonspace, each piston serving as an abutment for the motivefluid acting on the piston in advanc thereof, substantially as set forth.

2. The combination of a casing and a piston-hub which are rotatably mounted eccentrically relative to each other, pistons connecting said casing and piston-hub and adapted to be operated by motive fluid to rotate said casing and hub, and means independent of said pistons and connecting said casing and hub to cause the same to rotate together, substantially as set forth.

The described manner of mounting the 3. The combination of a casing and a piston-hub which are rotatably mounted eccentrically relative to each other, pistons connected to one of said parts and adapted to be operated by motive fluid to rotate said part, and means independent of said pistons and connecting said casing and hub to cause the same to rotate together, substantially as set forth.

4. The combination of a casing and a piston-hub which are rotatably mounted eccentrically relative to each other, pistons movably connected to said hub and adapted to be operated by motive fluid to rotate said hub, and means independent of said pistons connecting said casing and hub to cause the same to rotate together, substantially as set forth.

5. The combination of a rotary casing, a rotary piston-hub journaled eceentrically in said casing, pistons movably connected to said hub and casing and bridging the space between the hub and easing, means independent of said pistons for causing the casing and piston-hub to rotate together, and means for admitting an exhausting motive fluid to and from the space between the hub and easing, substantially as set forth.

6. The combination of a rotary casing, a rotary piston-hub journaled eccentric-ally in said casing, pistons pivotally mounted on said hub and having sliding and oscillating connections with said casing, and means for admitting and exhausting motive fluid to and from the space between said casing and hub, substantially as set forth.

7. The combination of a rotary casing, a piston-hub journaled eccentrically in said casing, pistons movably connected to said casing and hub and bridging the space between said casing and hub, means independent of said pistons connecting said casing and hub whereby the two are caused to rotate together, and means for admitting and exhausting motive fluid to and from the space between the easing and hub, substantially as set forth.

8. The combination of a rotary casing, a rotary piston-hub journaled eccentricall y in said casing, oscillating blocks journaled in said casing, pistons pivoted to said hub and having sliding connections with said oscillating blocks, and means for admitting and exhausting motive fluid to and from said casing, substantially as set forth.

9. The combination of a stationary shaft provided with an eccentric journal, a casing journaled to rotate on said shaft, a rotary piston-hub journaled on said eccentric journal, pistons movabl y connected to said casing and hub and bridging the space between said casing and hub, and means for admitting and exhausting motive fluid to and from said space between the-casing and hub, substantially as set forth.

10. The combination of a stationary shaft provided with an eccentric journal, a casing journaled to rotate on said shaft, a rotary pis ton-hub journaled on said eccentric journal, means connecting said casing and hub to cause the same to rotate together, pistons movably connected to said casing and hub and bridging the space between said casing and hub, and means for admitting and exhausting motive fluid to and from said space between the easing and hub, substantially as set forth.

11. The combination of a stationary hollow shaft divided to provide an inlet and an exhaust passage, a stationary hollow journal arranged eccentrically to said hollow shaft and divided into chambers communicating with said inlet and exhaust passages and having inlet and exhaust ports, a casing journaled to rotate on said shaft, a hollow piston-hub rotatabl y mounted on said hollow journal and provided with inlet and exhaust passages adapted to register with the inlet and exhaust ports in said journal, and pistons bridging the space between said casing and hub, substantially as set forth.

12. The combination of a stationary hollow shaft divided to provide an inlet and an exhaust passage, a stationary hollow journal arranged eccentrically to said hollow shaft and divided into chambers connnunicating with said inlet and exhaust passages and having inlet and exhaust ports, a casing journaled to rotate on said shaft, a hollow piston-hub rotatably mounted on said hollow journal and pro vided with inlet and exhaust passages adapted to register with the inlet and exhaust ports in said journal, means connecting said casing and hub to cause the same to rotate together, and pistons movably connected to said casing and hub and bridging the space between said casing and hub, substantially as set forth.

13. The combination of a stationary hollow shaft, divided to provide an inlet and an exhaust passage, a stationary hollow journal arranged eccentrically to said hollow shaft and divided into chambers communicating with said inlet and exhaust passages and having inlet and exhaust ports, a casing journaled to rotate on said shaft, a hollow piston-hub rotatably mounted on said hollow journal and provided with inlet and exhaust passages adapted to register with the inlet and exhaust ports in said journal, and pistons pivoted on said hub and having sliding and oscillating connections with said casing and bridging the space between the hub and easing, substantially as set forth.

la. The combination of a stationary hollow shaft divided to provide an inlet and an exhaust passage, a stationary hollow journal arranged eccentrically to said hollowshaft and divided into chambers communicating with said inlet and exhaust passages and having inlet and exhaust ports, a casing journaled to rotate on said shaft, a hollow piston-hub rota- W'itness my hand this 23d day of October, 1902.

WILLIAM M. HOFFMAN.

Witnesses:

JNo. J. BONNER, G. M. BENTLEY. 

